1. Field of the Invention
The present invention relates to angular position transducers of the type which provide an electrical signal which varies with angular position of a rotatable mechanical element to provide an indication of the angular position of the element.
2. History of the Prior Art
Angular position transducers are commonly used in various different applications where it is desired to provide a varying electrical signal to indicate the angular position of a mechanical element. Such transducers are useful, for example, in magnetic tape decks where they are employed to provide a constant indication of the angular position of pivotably mounted tension arms which engage the magnetic tape.
Angular position transducers of the electrical type commonly employ a primary winding or other means to induce magnetic flux in a rotatable mechanical element, from which the flux is sensed by one or more secondary windings. The amount of flux sensed by the one or more secondary windings provides an indication of an angular position of the rotatable mechanical element.
Prior art angular position transducers suffer from a number of disadvantages which may make them unsuitable for many applications of such devices. In one type of prior art arrangement in which the rotatable mechanical element is pivotably mounted so as to be movable relative to the opposite legs of an E-shaped core so as to vary the relative amounts of flux from a primary winding on the center leg of the core which flow into a pair of secondary windings on the opposite legs of the core, the resulting output signal typically varies with respect to the angular position of the rotatable mechanical element in relatively nonlinear fashion, due among other things to the nonlinear variation of the flux density with variation in the size of the air gaps. Still other transducers which rotate the rotatable mechanical element relative to a core in such a way as to vary the area of one or more air gaps while maintaining the depth of the air gap constant provide performance which is more linear in nature, but at the expense of considerable cost and complexity in the construction of the transducer. Still other arrangements in the prior art provide varying degrees of linearity in the performance thereof at the expense of other factors in the design or operation of the transducer.
Accordingly it would be desirable to provide an angular position transducer which is of relatively simple and inexpensive construction and yet which provides substantially linear performance over a wide range of possible angular positions.